Most men in their 40s do not have the speed and endurance of fit men in their 20s, but they still can do challenging and diverse workouts. The American Heart Association recommends that healthy men do at least 150 minutes of moderate to vigorous cardiovascular exercise every week. You should also do three 20-minute weightlifting, stretching and body resistance training sessions every week to build muscle, lubricate your joints and boost flexibility.
The heart of any 40- to 50-year-old man's fitness program should be cardiovascular exercise. Aim to raise your heart rate for at least 20 to 30 minutes. If high-impact workouts such as running, jumping rope and martial arts stress your joints and tendons, adopt a lower-impact workout such as climbing stairs, training on an elliptical machine, using a rowing machine or pedaling on a stationary cycle. You can make a low-impact workout more intense by speed-walking or hiking by adding a steady incline or hills to your route.
As men age, they gradually lose muscle mass. Men in their 40s can reverse this process by adopting a strength-training regimen. Lifting dumbbells, pumping hand weights, using resistance machines or doing calisthenics and floor work that use your own body weight as resistance builds muscle which raises your resting metabolic rate. Your body pumps more energy to your muscles, which makes you burn more calories around the clock. Target your upper body with pullups, biceps curls, triceps dips, standing flies and bench presses. Build lower body strength with squats, hamstring raises and lunges. Focus on your core by doing abdominal crunches while bicycling your legs or situps on an incline.
Getting fit and muscular does not always boost your flexibility. You need to stretch, bend and lubricate your joints to maintain your full range of motion as you age. After doing cardiovascular exercise, take time to do some forward bends, side stretches and overhead reaches. If you want more intense flexibility training, consider doing yoga poses. Power yoga, Ashtanga yoga and Bikram yoga are intense styles that also raise your heart rate and build muscle.
Reduce stress and the effects of aging by doing deep breathing exercises. In addition, breathing deeply while warming up for exercise gets your blood pumping and delivers oxygen to your muscles. Spend the first 10 minutes of your workout walking briskly or marching in place, and focus on inhaling deeply through your nose -- enough to fill your belly as well as your chest. Hold for a beat and then exhale deeply.